1. Field of the Invention
The present invention relates to an optical glass, to an optical element, to an optical system, and to an optical device.
2. Description of Related Art
Japanese Patent 4,610,046 disclosed that an optical glass that does not contain PbO, that has predetermined optical constants including refractive index nd of 1.52 to 1.58 and Abbe number νd of 50 to 57, and that has a negative anomalous dispersion.